Enhanced ammonia removal rate in a pilot-scale MBBR

A combined pilot-scale MBBR process was used for treatment of the wastewater in the Buji River in Shenzhen city. The averaged influent and effluent ammonia nitrogen concentrations were (25.88±7.73) mg/L and (1.11±1.93) mg/L, respectively. The results of the single factor experiments show that the biofilm fillers enhanced the ammonia removal and increased the specific ammonia oxidation rate by 25.5% to activated sludge. The specific rate decreased from 2.55 mg/(gMLVSS·h) to 1.91 mg/(gMLVSS·h) with the COD increasing from 139 mg/L to 587 mg/L, decreased from 8.24 mg/(gMLVSS·h) to 1.93 mg/(gMLVSS·h) with the MLVSS increasing from 0.45 g/L to 4.05 g/L, increased from 0.99 mg/(gMLVSS·h) to 2.89 mg/(gMLVSS·h) with the temperature increasing from 5°C to 35°C and increased from 0.62 mg/(gMLVSS·h) to 2.28 mg/(gMLVSS·h) with the DO concentration increasing from 0.5 mg/L to 4.0 mg/L, respectively. However, the volume ammonia oxidation rate increased linearly from 3.68 mg/(L·h) to 7.82 mg/(L·h) with the increased MLVSS (R = 0.967). The Arrhenius experience equation was used to describe the influence of temperature (R = 0.970). The Monod equation fitted the process well (R = 0.994) and the estimated half saturation constant of ammonia oxidation was 3.0 mg O /L.